Influence of Milling Conditions on the Behavior of AB5-Type Materials as Metal Hydride Electrodes

Abstract

A series of AB5-type alloys with different particle and grain size were characterized electrochemically as materials for negative electrodes in Ni-MH batteries. Besides, the effect of alloy composition on the discharge capacity and cycle life was studied. Ball milling under hydrogen atmosphere was applied to reduce significantly the grain size of the alloys and to avoid the initial activation at the electrochemical charge/discharge cycling. The alloy morphology and microstructure after different mechanical treatments were characterized by XRD and SEM. The best effect in respect of discharge capacity and cycle life was achieved for the materials milled for 5 h under hydrogen atmosphere.